JP5836618B2 - Epoxy resin composition and semiconductor device using the same - Google Patents

Description

  The present invention relates to an epoxy resin composition excellent in solder heat resistance and excellent in YAG laser marking properties and a semiconductor device sealed using the same.

  Semiconductor devices mainly sealed with an epoxy resin composition have traditionally marked semiconductor device manufacturers and manufacturing history with special thermosetting or UV curable inks. Due to the time required and the handling of the ink is not easy, the number of electronic component manufacturers adopting laser marking is increasing recently. The marking on the surface of the molded product of the epoxy resin composition by short-time irradiation of YAG or carbon dioxide laser light has better workability than marking with ink, and it can be completed in a short time. It is a method with many advantages.

  However, when laser marking is performed on the surface of an encapsulated molded product of a semiconductor device encapsulated with a conventional epoxy resin composition, the contrast between the marked part and the unmarked part is unclear, and the printing is yellow. For this reason, it is difficult to read the print. c Regarding carbon dioxide laser marking, an effective colorant has already been developed, and a resin composition capable of obtaining a clear print has been put on the market.

  On the other hand, regarding YAG laser marking, for example, according to JP-A-2-127449, “carbon black having a carbon content of 99.5% by weight or more and a hydrogen content of 0.3% by weight or less” has the same purpose. Although it is described as being effective, and various other studies have been made, the marking contrast after the carbon black is volatilized is still insufficient, and a clear print cannot be obtained. Furthermore, in Japanese Patent Application Laid-Open No. 2000-128960, good laser marking is achieved by using carbon black having a DBP absorption of 80 ml / 100 g or more and an average particle size of 20 nm or more and a biphenyl type epoxy resin. Although it is believed to be obtained and its effect is recognized, a resin composition that can meet the recent demand for further soldering heat resistance is desired.

  An object of the present invention is to provide an epoxy resin composition having excellent laser marking properties and solder heat resistance, and a semiconductor device having excellent laser marking visibility by sealing using the epoxy resin composition.

The present inventors have made intensive studies, as a result, the carbon black DBP absorption is 100 cm ^3/100 g or more as the colorant, the average particle diameter 0.1~10μm crushed silica or average particle size of 1 to 100 nm, We have found that an epoxy resin composition having excellent laser marking properties and solder heat resistance and a sealed semiconductor device can be obtained by using an inorganic filler containing ultrafine fine spherical silica, which has led to the solution of this problem. .

The present invention mainly has the following configuration. Namely, in epoxy resin composition mainly composed of "epoxy resin, a curing agent and an inorganic filler, DBP absorption amount of carbon black is used at 100 cm ^3/100 g or more as the colorant, the average particle size of the inorganic filler It is an “epoxy resin composition characterized in that it contains at least one of crushed silica of 0.1 to 10 μm or ultrafine fine spherical silica having an average particle diameter of 1 to 100 nm”.

  A semiconductor device using this exhibits excellent laser marking properties, can provide a clear marking, and is also excellent in solder heat resistance.

The present invention uses carbon black DBP absorption is 100 cm ^3/100 g or more (D) as a colorant, and the average particle size 0.1~10μm crushed silica inorganic filler (C) (c1) or average It is a resin composition containing a very fine spherical silica (c2) having a particle diameter of 1 to 100 nm, and a semiconductor device encapsulated using this resin composition has both excellent YAG laser marking properties and solder heat resistance. is there.

Hereinafter, the configuration of the present invention will be described in detail.
The epoxy resin composition of the present invention, the epoxy resin composition of the epoxy resin (A), the curing agent (B) and the inorganic filler (C) as main components, DBP absorption amount is 100 cm ^3/100 g or more Carbon black (D) is used, and the filler (C) contains at least one of crushed silica (c1) having an average particle diameter of 0.1 to 10 μm or ultrafine spherical silica (c2) having an average particle diameter of 1 to 100 nm. This is an epoxy resin composition that is essential.

  The epoxy resin (A) used in the present invention is not particularly limited as long as it has two or more epoxy groups in one molecule. For example, cresol novolac type epoxy resin, phenol novolac type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, dicyclopentadiene phenol type epoxy resin, naphthalene type epoxy resin, alicyclic epoxy resin, Examples include heterocyclic epoxy resins, spiro ring-containing epoxy resins, and halogenated epoxy resins. Two or more of these epoxy resins may be used in combination. From the viewpoint of mechanical properties and solder heat resistance, the biphenyl type epoxy resin (a1) represented by the general formula (I) or the bisphenol represented by the general formula (II) -The F type epoxy resin (a2) is preferable. Furthermore, it is possible to use both the biphenyl type epoxy resin (a1) represented by the general formula (I) and the bisphenol F type epoxy resin (a2) represented by the general formula (II). In this case, the general formula (I) The total of the biphenyl type epoxy resin (a1) represented by general formula (II) and the bisphenol F type epoxy resin (a2) represented by general formula (II) is preferably 80% by weight or more in the epoxy resin.

  The compounding quantity of an epoxy resin (A) is 0.5 to 15 weight% normally with respect to the whole epoxy resin composition from a viewpoint of a moldability and adhesiveness, More preferably, it is 2 to 10 weight%. If the blending amount of the epoxy resin (A) is 0.5% by weight or more, the moldability and adhesion will not be insufficient, and if it is 15% by weight or less, the linear expansion coefficient of the cured product will increase. Further, it is not difficult to reduce the stress of the cured product.

  If the hardening | curing agent (B) used for this invention hardens an epoxy resin, the kind in particular will not be limited. For example, phenol novolak resin, cresol novolak resin, phenol resin, various novolak resins synthesized from bisphenol A and resorcin, polyhydric phenols, acid anhydrides such as maleic anhydride, phthalic anhydride, and metaphenylenediamine, diaminodiphenylmethane And aromatic diamines such as diaminodiphenylsulfone. Among these, a phenolic curing agent is preferably used for semiconductor encapsulation from the viewpoint of heat resistance, moisture resistance and storage stability, and two or more curing agents may be used in combination depending on the application.

  In this invention, the compounding quantity of a hardening | curing agent (B) is 0.5 to 15 weight% normally with respect to the whole epoxy resin composition, Preferably it is 1 to 10 weight%. Furthermore, the compounding ratio of the epoxy resin (A) and the curing agent (B) is such that the chemical equivalent ratio of (B) to (A) is 0.5 to 1.5, particularly 0 from the viewpoint of mechanical properties and moisture resistance reliability. Preferably it is in the range of 7 to 1.2.

  The present invention includes an inorganic filler (C). Specific examples include amorphous silica, crystalline silica, calcium carbonate, magnesium carbonate, alumina, magnesia, magnesium oxide, zirconia, zircon, clay, talc, calcium silicate, titanium oxide, antimony oxide, asbestos, glass fiber, etc. Is mentioned. Silica, alumina and zirconia are preferable, and silica is more preferable. These inorganic fillers may be used alone or in combination of two or more. The shape and particle size of the filler (C) are not particularly limited, but it is preferable from the viewpoint of fluidity to contain spherical particles having an average particle size of 3 μm or more and 40 μm or less in the filler (C).

  The average particle diameter here means a particle diameter (median diameter) at a cumulative weight of 50%. In the present invention, the proportion (D) of the inorganic filler is required to be 83 to 95% by weight of the entire resin composition from the viewpoint of flame retardancy, fluidity, low stress and adhesion, and preferably 85. ~ 93 wt%.

  In the present invention, the inorganic filler (C) contains at least one of crushed silica (c1) having an average particle diameter of 0.1 to 10 μm or minimal fine spherical silica (c2) having an average particle diameter of 1 to 100 nm. is important. By containing at least one of crushed silica (c1) or ultrafine silica (c2) having an average particle size of 0.1 to 10 μm, further superior laser marking and solder heat resistance can be obtained. The crushed silica (c1) and the ultrafine spherical silica (c2) having an average particle diameter of 1 to 100 nm are both contained at a ratio of 1 to 30% by weight with respect to the whole inorganic filler (C). Weight percent is more preferred. Furthermore, it is also preferable to contain both crushed silica (c1) having an average particle size of 0.1 to 10 μm or ultrafine spherical silica (c2) having an average particle size of 1 to 100 nm.

  By containing at least one of the crushed silica (c1) and the ultrafine spherical silica (c2), further superior laser marking and solder heat resistance can be obtained. The crushed silica (c1) and the ultrafine silica (c2) are not particularly limited in specific surface area and particle size distribution other than the average particle size.

In the present invention, DBP absorption amount of carbon black is 100 cm ^3/100 g or more (D) is used as a coloring agent. The DBP absorption is determined by the following method. That is, 20 g of the sample dried for 1 hour at 150 ± 1 ° C. is put into the mixing chamber of the abstract meter, and the rotating machine of the mixing chamber in which the limit switch is set at a predetermined position is rotated. At the same time, DBP (specific gravity 1.045 to 1.050) is started to be added from the self-running burette at a rate of 4 ml / min. As the end point is approached, the torque increases rapidly and the limit switch is turned off. It DBP amount added up (cm ³⁾ than the DBP absorption amount (cm ³ / 100g) obtained by the following equation.

DBP absorption (cm ³ / 100g) = DBP amount (cm ³⁾ / sample weight (g) × 100 mosquitoes - the DBP absorption of carbon black is 100 cm ^3/100 g is not obtained satisfactory laser marking properties in the following. By using the carbon black of 100 cm ^3/100 g, it is the satisfactory laser marking is obtained. Although if 100 cm ^3/100 g or more but sufficient effect can be obtained, preferably DBP absorption in order to obtain a better laser marking properties 110 cm ^3/100 g or more carbon black, more preferably DBP absorption it is preferable to use a 120cm ³ / 100g or more of carbon black.

Average particle size, specific surface area and pH of the carbon black (D) in the present invention, DBP absorption amount is not particularly limited as long as 100 cm ^3/100 g or more.

  Further, the blending amount of the carbon black (D) with respect to the entire resin composition is not particularly limited, but in order to obtain better laser marking properties, it is preferably 0.1 to 0.6% by weight, more preferably 0.2. ~ 0.4 wt% is good.

The pyrogenically as a method of DBP absorption obtain 100 cm ^3/100 g or more carbon black (D), it may be any produced by incomplete combustion method or the like, not particularly limited in its production method. Result DBP absorption it is sufficient that a 100cm ³ / 100g or more as.

  In the present invention, a curing accelerator that accelerates the reaction between the epoxy resin and the curing agent may be used. The type of the curing accelerator is not particularly limited as long as it accelerates the curing reaction. Specifically, various imidazole compounds, various amine compounds, various organometallic compounds, various organic phosphine compounds and the like are preferably used. These curing accelerators may be used in combination of two types depending on the application. Of these, organic phosphine compounds are preferably used from the viewpoint of moisture resistance. These curing accelerators (C) may be used in combination of two or more depending on the application, and the addition amount is preferably in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the epoxy resin (A). .

  Furthermore, the present invention includes various stress reducing agents such as elastomers, various coupling agents such as silane coupling agents and titanate coupling agents, halides such as halogenated epoxy resins, various flame retardants such as phosphorus, antimony compounds and the like. Various additives such as flame retardant aids, various colorants other than carbon black, various release agents such as long-chain fatty acid esters, long-chain fatty acid amides, and the like can be arbitrarily added as long as the characteristics of the present invention are not impaired. The coupling agent can be surface-treated with an inorganic filler in advance.

  As a manufacturing method of the epoxy resin composition of this invention, it is preferable to melt-knead. For example, various raw material components are mixed (dry blended) by a known method such as a mixer, and then melt kneaded using a known kneading method such as a Banbury mixer, a kneader, a roll, a single or twin screw extruder, and a kneader. Thereafter, it is produced by solidification, pulverization, and tableting or pelletizing as necessary. And a semiconductor device can be obtained by sealing a semiconductor element by transfer molding etc., using the tablet, pellet, and powdery resin composition which were obtained in this way, for example.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these.

[Reference Examples 1 to 9, Examples 10 to 17 , References 18, 19, and 20, Comparative Examples 1 to 5]
<Preparation of epoxy resin composition>
The raw materials shown in Table 1 were blended at the composition ratios shown in Tables 2 to 4, and blended with a mixer. These mixtures were melt-kneaded at a resin temperature of 90 ° C. using a twin screw extruder, then cooled and pulverized to obtain an epoxy resin composition.

<Creation of sample for evaluation>
After the resin composition powder is compression-molded into a tablet shape (tablet filling rate is 95.0 to 98.5%), 160 pin QFP (Quad Flat Package) (external dimensions: 24 mm × 24 mm) using a transfer molding machine × 3.4 mmt) was molded under the conditions of a molding temperature of 175 ° C., an injection time of 7 seconds, a molding pressure of 9.8 MPa, and a molding time of 2 minutes, and this was post-cured at 175 ° C. for 10 hours to obtain a semiconductor device. It was.

<Evaluation of laser marking visibility>
Using a YAG laser “Marker MY9500” manufactured by Keyence Corporation on the surface of the cured body of the obtained semiconductor device, the laser wavelength was 1.06 μm, the laser output was 14 A (ampere), the character width was 0.9 mm, and the character thickness was 0. Marked with 1 mm. Visibility was evaluated using STOUFFER GRAPHIC ARTS EQUIIPMENT CO. 21 Step Sensitivity Guide (Evaluation of Visibility by Films with Different Blackness of 1 to 21. The larger the number, the better the visibility. The optical density D is 0.05 in Step 1 and 0.20 in Step 2. 0.35 at step 3, 0.49 at step 4, 0.64 at step 5, 0.79 at step 6, 0.93 at step 7, and so on until step 21. Here, optical density D is incident light. If the intensity is I ₀ (mJ / cm ² ), and the intensity of transmitted or reflected light is I (mJ / cm ² ), it is defined as in formula (III).
Optical density D = log ₁₀ (I ₀ / I) (III)
A 21-step sensitivity guide was placed on the printed part of the surface of the cured body of the semiconductor device so that the printed part could not be read, and the indicated value of the 21-step sensitivity guide was measured.

<Evaluation of solder heat resistance>
Sixteen 160pinQFP molded and post-cured semiconductor devices were humidified at 85 ° C / 85% RH for 120 hours, passed through an infrared reflow furnace (245 ° C), and the number of cracks generated in 160pinQFP was measured externally. And the inside were examined by an ultrasonic flaw detector. Based on the total number of cracks (total of 16 packages), the evaluation was made in the following six stages.
A: 0 (pieces / 16 package)
B: 1-2 (pieces / 16 package)
C: 3-6 (pieces / 16 package)
D: 7-10 (pieces / 16 package)
E: 10-15 (pieces / 16 package)
F: 16 (pieces / 16 package)

<Evaluation results>
The evaluation results are shown in Table 5.

Using carbon black DBP absorption is 100 cm ^3/100 g or more as seen in Example 10 to 17 and the in the inorganic filler that contains a minimum fine spherical silica having an average particle diameter 1~100nm as essential A semiconductor device encapsulated with an epoxy resin composition using a biphenyl type epoxy resin or a bisphenol F type epoxy resin as an epoxy resin is excellent in laser mark visibility and solder heat resistance. Meanwhile, system without addition of crushed silica or a minimum fine spherical silica in the inorganic filler as seen in Comparative Examples 1 to 5, DBP absorption amount of 100 cm ^3/100 g or more mosquito - In systems using no carbon black, visible Inferior property and solder heat resistance.

Claims (3)

A method for producing a tablet, pellet or powdery epoxy resin composition for encapsulating a semiconductor element, wherein the production method comprises an epoxy resin (A), a curing agent (B) , an inorganic filler (C ) and mixed carbon black (D), and melt-kneaded, after solidification, comprises the step of pulverizing, der weight of carbon black (D) is DBP absorption is 100 cm ^3/100 g or more
And the inorganic filler (C) contains ultrafine fine spherical silica (c2) having an average particle diameter of 1 to 100 nm, and the epoxy resin (A) has a structure represented by the following formula (I) (a1 Or a bisphenol F-type epoxy resin (a2) having the structure of the following formula (II): a method for producing an epoxy resin composition for semiconductor encapsulation.

A method for producing an epoxy resin composition for encapsulating a semiconductor , characterized in that the marking visibility of a printed part is 5 or more by evaluation using a 21-step sensitivity guide, wherein the printed part is the semiconductor On the surface of the cured epoxy resin composition for semiconductor encapsulation of the 160-pin QFP molded at 175 ° C. for 2 minutes and post-cured at 175 ° C. for 10 hours using the sealing epoxy resin composition, a laser wavelength of 1. The manufacturing method of the epoxy resin composition for semiconductor sealing of Claim 1 which is marked by 06 micrometers, laser output 14A, character width 0.9mm, and character thickness 0.1mm . A method for producing a resin-encapsulated semiconductor device, comprising: a process for producing an epoxy resin composition for semiconductor encapsulation; and a process for encapsulating a semiconductor element with the epoxy resin composition for semiconductor encapsulation. manufacturing process of the sealing epoxy resin composition is intended to include a method of manufacturing a semiconductor encapsulating epoxy resin composition according to claim 1 or 2, the manufacturing method of the resin-sealed semiconductor device.